We have 4" Serta memory foam on ALL of the beds in our home, and at our vacation homes. Even new mattresses get covered with memory foam. I have purchased them as gifts for my parents and grown children as well. These have to be exceptionally wonderful to buy so many of them! When we traveled to Europe, I packed a twin size and took it with me, because I knew I would not sleep without one! I guess that says it all! So many guests have inquired as to where to purchase the super comfy toppers after experiencing the 'sleep of their lives'. I only wish I had stock in the company!